The present invention relates to a generator responsive to water current for generating electricity and particularly relates to an underwater electrical current generator having turbine blades rotatable about a center body.
With increasing demand for environmentally friendly electrical power generation, many alternatives to carbon produced electrical power have been proposed. For example, in U.S. Pat. No. 3,209,156 there is disclosed an underwater generator for supplying limited electrical power to underwater measuring and sensing units. The supplied electricity provides power for underwater communications and management of oceanographic instrumentation. The generator in the afore-mentioned patent includes a central housing mounting a plurality of circumferentially spaced blades which rotate a hub journaled on the housing such that an arrangement of permanent magnets and stator windings generate electricity for powering the instrumentation. The disclosed generator, however, turns at relatively low speed compared to conventional turbines and the resulting power production potential is quite low. Commercial generation of electricity for land use is not particularly feasible employing the construction of that patent. Accordingly there is a need to develop an underwater current generator for producing electricity for commercial land uses.
In a preferred embodiment of the present invention, there is provided an electrical generator for disposition in a water current comprising: a central body carrying a plurality of stator coils within the body and defining a generally longitudinal axis; a pair of annular hubs rotatable about and carried by the central body, each of the hubs mounts a plurality of turbine blades and a plurality of magnets for generating magnetic flux, the hubs being located about the stator coils enabling generation of electricity by the interaction of the magnetic flux and the coils in response to rotation of the blades and hubs about the central body; the blades being raked back in the direction of the water current and having free ends.
In another embodiment of the present invention, there is provided an electrical generator for disposition in a water current comprising a central body carrying a plurality of stator coils within the body and defining a generally longitudinal axis; a pair of annular hubs rotatable about and carried by the central body, each of the hubs mounting a plurality of turbine blades and a plurality of magnets for generating magnetic flux, the hubs being located about the stator coils enabling generation of electricity by the interaction of the magnetic flux and the coils in response to rotation of the blades and hubs about the central body; at least portions of the blades being rotatable about axes non-parallel with the longitudinal axis to enable rotational movement of said blade portions.